Circular  N 


United  States  Department  et  Agriculture, 


BUREAU   OF   ENTOMOLOGY 
L.   O.   HOWARD.  Entomologist  and  Chief  of  Bureau. 


THE  ALFALFA   a  ILL  IIDGE. 

•  I  tphondylla  miki  Waciitl,  i 

By   r.  M.   \\  i  BS1 i  n. 
In  clan  *  •;/  urn}  Foragi   Insert  Investigation*. 

I  STBODl  i  TION. 

The  object  in  publishing  ;i  circular  mi  the  alfalfa  gall  mi« I^r«* 
(Asphondylui  miki  Wachtl)  at  the  present  time  is  to  direct  the  atten- 
tion, especially  of  alfalfa  growers  in  the  southwest 
era  portion  of  the  country,  t<>  the  appearance  of  this 
foreign  insect  in  the  United  States,  with  the  hope 
thai  they  will  be  led  to  observe  the  galled  pods 
shown  in  figures  1.  2,  ;m<l  ;,>  :in<l  report  the  occur- 
rence <>f  the  same  to  this  bureau. 

\-  a  matter  of  fact,  we  do  not  knew  and  ean  not 
foresee  what  injuries  thi-  insect  will  cause  in  this 
itry,  though  it  has  not  so  fai  proved  destructive. 
We  do  not  m  i-h  M  cause  any  1 1 mint*  apprehension 
relative  to  its  effects,  but  feel  that  we  ought  to  bring 
it-  presence  in  alfalfa  fields  te  the  attention  of 
farmers,  w  that  it  may  be  earefnlly  watched. 

It  has  n«>t.  therefore,  been  thought  necessary  to 
publish  here  ;i  full  technical  description  of  tin-  midge 
beyond  what  i-  shown  in  the  illustration  (fig.  1). 

Galls,  from  which  this  insect  was  afterwards 
reared,  were  first  found  in  limin><l  numbers  by  Mr. 
('.  N.  Ainslie,  of  this  bureau,  at  Sacaton,  Ariz.,  on 
the  Pima  Indian  Reservation,  June  12,  1909.  Grails 
identical  with  these  were  also  found  in  the  same 
locality  by  Mr.  V.  L.  Wildermufh,  of  this  bureau, 
June  10.  1910.  They  were  found  ahout  Tempe  and  Phoenix,  Ariz., 
June  in,  1011.  by  Mr.  E.  I  >.  Smyth,  of  this  hureau.  in  ahout  the  same 

76"— Clr.  147— U* 


I'l.;.    1.       A    hpnel  of 
alfalfa     with     all 

of     Hi. 

I   by   t ho  nl- 

f:ilfn     irnll     inlilc 

h  u  n  ,1  ]i  1  i  <i 
iiiiAii    OKCpt    thi> 

uppermost  which 

htly  nf- 
Sllchtly 
enlarged.      (Orig- 
inal.) 


THE    ALl'ALFA    GALL    MIDGE. 


numbers  as  previously  observed  by  him  at  Sacaton,  May  27,  1911. 
In  sending  a  lot  of  heads  of  alfalfa  from  Tularosa,  N.  Mex.,  July 
13,  1911,  Mr.  M.  A.  Bishop,  a  farmer,  directed  our  attention  to 
reports  among  his  neighbors  of  injury  to  the  seed  and  complaints 
of  bee  keepers  of  a  lack  of  honey  in  the  bloom.  A  considerable 
number  of  these  galled  pods  was  included  in 
his  sending,  apparently  without  having  been  ob- 
served by  him. 

DESCRIPTION    or   Till:    CALL. 

The  following  is  a  translation  of  the  original 
dascription  of  the  gall  (fig.  3)  found  in  alfalfa 
fields  in  the  vicinity  of  Vienna,  Austria: 

The  formation  of  the  gall  stands  out  as  a  deformation 
of  the  seed-pod  of  the  lucerne.  Medicago  sativa  L.  The 
deformed  pod  does  not  show  the  same  snail  coil  shape  as 
in  the  normal,  healthy  condition,  but  it  is  shortened  at  the 
point,  where  it  is  somewhat  shrunken.  It  is  strongly 
bloated  up  and  swelled  out,  particularly  in  the  proximity 
of  the  base,  the  valves  of  the  pod 
are  considerably  thicker,  and  the 
rest  of  it  is  flesh-like  in  color. 
Although  the  pods  keep  the  green 
color  on  the  outside,  they  contain 
no  seed.  It  is  not  impossible 
that  the  insect,  by  visiting  in 
large  numbers  fields  containing 
lucerne,   might    injure   the    seed 

harvest  of  this  clover  species  quite  considerably. 

The  pupa  bores  through  the  wall  of  this  pod  with  the 

intention    of   transforming    to    the   imago.     It    is    then 

situated  laterally  and  below  the  shrunken  gall  point. 

On  Medicago  falcata  L.  I  have  found  exactly  the  same 

gall  formation,  but  only  a  few  examples.     Although  I  did 

not  take  the  flies  out  of  these  galls,  I  do  believe,  never- 
theless,  that   these  galls   in   their  formative  condition 

agree  exactly  with  those  of  the  preceding  species,  and 

since   one   out   of    the   same   conspicuous    pupal    cases 

belongs  to  an  Asphondylia,  I  dare  to  conclude  therefrom 

that  their  origin  may  be  traced  to  Asphondylia  miki.* 

The  description  of  the  gall  forms  on  both  species  of 

Medicago  are  taken  from  Donau-Auen  of  Wien. 

From  the  galled  seed  pods  found  by  him  at  Sacaton,  Mr.  Ainslie 
was  able  to  rear  the  adult  insects  (fig.  4),  which  were  later  deter- 
mined by  the  late  Mr.  D.  TV.  Coquillett  as  Asphon-dyVia,  mdlci,  as 

1  (J.  IMtter  v.  Frauenfeld  had  already  become  acquainted  with  this  gall  formation  for  in 
the  Verb,  d.  k.  k.  zool.-hotan.  Ges.,  Jahrg.  1861,  Bd.  XL  p.  17.°..  ho  says:  "The  Oall  flies 
inhabit  the  flowers  of  the  Medicago  sativa  L.  in  large  numbers,  and  the  fruit  of  Medicago 
in  even  greater  numbers."  [KaiBerlich-kSnigliche  Zool.-bot.  Ges.  in  Wien.,  vol.  30,  p.  035, 
2  tab.  XVIII.  tig.  2,   1880.] 


Fig.  2. — A  head  of  al- 
falfa with  the  seed 
pods  uninjured  ex- 
cepting the  lower 
one  at  right,  which 
has  been  attacked 
by  the  alfalfa  gall 
midge.  Slightly  en- 
larged.    (Original.) 


Fig.  3. — A  single  seed 
pod  of  alfalfa  de- 
stroyed by  the  alfalfa 
gall  midge.  Much  en- 
larged.  .(Original.) 


I'll  I      \l.r  \l.l   \    UALL    \l  1 1  m  ;  i 


described  in  1880  from  the  vicinity  of  Vienna*  Austria,  where  the 
species  appears  to  affed  alfalfa  in  precisely  the  same  way  as  in 
Arizona  and  New    Mexico. 

I  III      \D\  I   l     M  ll'i.i  .  "^  /      / 

This  midge  belongs  w  ith 
:i  group  of  flies  w  hich  in- 
cludes tlic  wheal  midge 
\i  ohtarinia  tritici  Kirby), 
the  clover  midge  ( l><>s>i- 
)u  ura  h  guminicola  Lintn.), 
and    the    sorghum    midge 

■  a  fa  /-in  in  8orgh  1 1  a  J  n 

.).  The  insects  are 
very  small  and  obscurely 
colored,  90  that  the  fanner 

will     hardly    ho    likely    to 
observe    them.     He    will. 
however,  have  no  difficulty 
in  detecting  the  galled  9eed 
pods.       During    the     last 
year  or  two  a   Dumber  of 
complaints  have  been   re- 
ceived from  the  Southwest 
relative  to  the  failure  of  alfalfa  seed  to  develop.    This  has  been 
attributed  by  farmers  i<>  a  number  of  insects,  hoik-  of  which  i-  al 
all  likely  to  1.,.  responsible  for  the  injury,  while  it   is  quite  possible 
that    it    may  he  due   to  this  gall   midge. 
1111:   i-i  r  \. 

The  pupa  is  shown  in  figure  •">.  The  dor- 
sum, or  hack,  i-  illustrated  in  figure  •">.  ./. 
which  shows  the  -pine-  that  enable  it  to  work 
it>  way  through  the  wall-  of  the  galled  pod, 
a-  described  in  the  preceding  translation. 


1      ill.-  ni falfn  gall  midge:  Adult  female,  with 
antenna  of  male  above,  al  left.    Greatly  enlai 

-   n;ll    . 


Pi  ■  •"  The  alfalfa  gall 
midge:  «7.  Papa,  dorsal 
v  law,  showing  the  spines 
:!h>  back,  by  the  aid  of 
arnica  it  works  Itself  oul 
of  tba  galled  pod  :  b,  van 
tral  or  under  side  of 
OreaUj  enlarged. 
1  '^rlidnnl  i 


11  w.i  1  -   OF    nil     1  \-i  1  1. 

We  hive  not.  up  to  the  present  time,  been 

able  to  secure  very  much  definite  information 

relative  to  the  pest      From  the  notes  made  by 

Mr.  A in-lie  and  also  by  Mr.  Smyth,  it  would 

appear  that  the  insect   winter-  in  the  pod-. 

So  tar  as  i-  now  known  it-  breeding  season  during  summer  i-  rather 

short,  a-  it  ha-  not  been  noticed  earlier  than   late  May  or  later  than 

September,  excepting  that  Mr.  Aim-lie  reared  adults,  in  confinement, 


UNIVERSITY  OF  FLORIDA 


THE    ALFALFA   GALL   M ~. 


3  1262  09216  5660 


as  late  as  October  26.     This  late  date  would  indicate  an  emergence 
in  .spring,  rather  than  in  late  fall,  under  natural  conditions. 

OBSCURITY  SURROUNDING  ITS  APPEARANCE. 

That  the  insect  should  first  make  its  appearance  in  the  midst  of  a 
desert  country  (see  fig.  (5)  is  somewhat  surprising.  There  is  nothing 
known  of  it  that  would  lead  us  to  believe  that  it  can  l>e  distributed  in 
alfalfa  seed.  It  could  hardly  have  been  imported  accidentally  from 
the  Eastern  Hemisphere  into  this  part  of  the  country.  Besides  this, 
it  is  preyed  upon  extensively  by  parasitic  insects,  which  would  imply 
a  rather  long  residence  in  this  country,  although  as  these  parasites  are 
all  new  to  science  and  have  never  been  described, 
it  would  almost  seem  that  it  might  be  working  it- 
way  from  Mexico  northward.  The  abund 
of  these  parasites  is  an  encouraging  feature,  at 
they  tend  to  prevent  its  becoming  destructive. 

"With  the  additional  information  which  we 
hope  to  obtain,  both  from  investigations  of  the 
bureau  and  from  those  into  whose  hands  this 
circular  may  fall,  we  shall  probably  be  able  to 
dispel  much  of  the  obscurity  at  present  sur- 
rounding the  pest.  The  indications  are  that  it 
is  spreading  over  the  alfalfa-growing  sections  of 
the  extreme  Southwest,  but  it  does  not  neces- 
sarily follow  from  this  that  it  will  prow 
destructive  as  have  many  other  insects  coming 
to  us  from  across  the  Atlantic  Ocean. 

PREVENTIVE   MEASURES. 

It  is  yet  too  early  to  say  much  concerning  measures  for  preventing 
injury  by  the  alfalfa  gall  midge.  Of  course,  mowing  the  alfalfa  j 
as  the  plants  are  coming  into  bloom  will  doubtless  keep  the  numbers 
ci'  the  midge  much  reduced,  as  this  method  tends  to  prevent  develop- 
ment, and.  therefore,  to  curtail  increase  in  numbers.  A  significant 
observation  made  at  Sacaton.  Ariz..  May  27.  1011.  by  Mr.  Smyth,  is 
quite  suggestive.  "The  galls  were  found  very  sparingly  in  fields 
which  had  been  cut  for  hay  less  than  two  months  since,  and  in  such 
fields  from  none  of  the  galls  had  the  adults  issued.  But  in  one  field  of 
both  purple  and  yellow  flowering  alfalfa,  which  had  not  been  from 
early  spring  at  any  time  cut  for  hay.  but  rather  allowed  to  run  to 
seed,  the  galls  were  far  more  plentiful  than  in  other  field-,  and  from 
a  large  percentage  of  them  adults,  or  parasites,  had  issued." 

A}jp  roved : 

James  Wilson, 

Secretary  of  Agriculture. 

Washington.  D.  C..  January  '/.  1912. 

O 


Fig.  6. — Map  showing 
localities  where  1  lie 
alfalfa  gall  midge  has 
been  found  in  the 
United  States.  (Orig- 
inal, i 


